Technologies have known a rapid and a spectacular development in recent decades. Also, more and more people get involved in bustling life in this competitive world. Convenient transportation further contributes much to the booming business. In one aspect, for many people telecommunication equipment such as telephones are essential to their daily life. People think that good telecommunication equipment is capable of increasing working efficiency. In an emergency, such telecommunication equipment may save people' life. In this regard, a user may always want his/her telecommunication equipment to maintain operable all the time. Hence, all telecommunication equipment providers endeavor to satisfy such demand of users.
Recently, newly available network communication equipment such as Voice Over IP Device (VoIP) or modem is capable of providing inexpensive long distance (or international) calls. Hence, users may find that they can save a significant amount of telecommunication charge by using such network communication equipment instead of conventional Public Switching Telephone Network (PSTN) in communication. In a survey conducted by telecommunication equipment manufacturer, more than 70% of PSTN users would like to switch to use network communication equipment in communication after considering the saving of fee.
A typical network communication equipment (e.g., VoIP or modem) 11 is shown in FIG. 1. As shown, an adapter 12 interconnects network communication equipment 11 and a plug 13 capable of inserting into an outlet of external power. It means that network communication equipment 11 is externally powered. At least one telephone 10 is coupled to network communication equipment 11 so that voice signals from telephone 10 may be converted into digital signals in network communication equipment 11. Digital signals are further processed to form IP packets prior to transmission. In detail, formed IP packets in network communication equipment 11 are sent to Internet server 15 through network switching apparatus 14. Further, user may communicate with other people having the same network communication equipment through server 15.
However, the previous configuration suffered from a disadvantage. As stated above, network communication equipment 11 is externally powered. Hence, network communication equipment 11 is inoperable when power is out. As an end, communication is interrupted. Such communication interruption may cause inconvenience or even serious consequences.
Thus, it is desirable to provide an improved network switching apparatus for supplying power to network communication equipment through twisted pair line. It utilizes power of network switching apparatus for maintaining an ongoing communication with remote telephone when power out occurs. Whereby, it is possible of overcoming the above drawback of prior art, i.e., communication interruption due to power out.